Thinkpads Forum

I have been having problems adjusting the battery charge thresholds.
Because I use my X40 mostly on AC I would like to change the “start charging when below:” threshold to around 70%

The problem is that every time I run the notebook on batteries and reconnect it, (or simply just restart the computer), the value gets changed back to 96%. This happens regardless if I have the “Automatically determine the charging threshold…” enabled or disabled.

Am I the only one with this problem? Is it possible to change this value somewhere else that in the “Improve battery health”?

I have not experienced the problem you are having on either my T42 or x40. I do not have the “Automatically determine the charging threshold" enabled. I have my start charge set to begin when below 70% and to stop charging at 95%. It holds these settings when switching between Bat. or AC and after shut downs or restarts.

jmt: what's the benefit of doing a 70% start charge and a 'do not charge' above 95%? Is it better for the battery?

DavidNZ wrote:jmt: what's the benefit of doing a 70% start charge and a 'do not charge' above 95%? Is it better for the battery?

Yes, a battery's life span is determined by the number of cycles it has. A cycle is determined by one charge equals one cycle. It doesn't matter weather the charging begins at 96% or 10%. Obviously if the charging begins at 70% instead of 96% the number of cycles over any given time are going to be considerably less which means longer battery life. Also continuing to charge the battery above 97% ads considerably more heat and stress to the battery with very little added benefit. Lastly if you do follow this schedule, about every 60 to 90 days you should allow your battery to drain to aprox. 2% and than charge to 100%. This program has given me batteries that have been able to maintain full charging capacity over a period of four years or longer.

Hmmm...cheers - something to think about. Have been letting mine sit at 100% most of the time with AC in. Don't use battery all that often.

Where is this option that tells the TP to "start" and "stop" charging at certain %'s?

I have a T42p, BTW.

Left click your battery max gauge and click on "improve battery health" in the menu that appears.